Hi! I am new to this forum and also new to modifying/fixing snes consoles. I have my original SHVC NTSC console from the United States which I bought many years ago. It has always worked perfectly until a few months ago when the video image suddenly lost all colors and got an inverted (negative) black and white picture. I am connecting my snes to my HDTV through an RGB SCART cable connected to an OSSC line doubler. The cables and OSSC are not the issue because I have tested them with my RGB-modded SNES mini console and have not had a problem.
I have tried to fix the issue by doing the following:
Replaced all smd capacitors with brand new capacitors bought from console5.
Replaced the 21.4772 crystal oscillator with a brand new one.
Checked connectivity of everything that I could test on the mother board, but found no issues.
Replaced the voltage regulator with a 5-volts, 2 amp regulator bought from console5 as well.
Since none of the above seemed to fix the problem, I tried soldering pins 20, 21 and 22 from the BA6592F video encoder directly to the corresponding RGB pins of the multi-out through a cable and 75ohm resistors, and did the same for the csync, but connected it directly without a resistor.
After this, I still got the same black and white inverted (negative) image.
I then tried soldering a 470 uf, 6.3 v capacitor to legs 2 and 3 of the voltage regulator. Amazingly, I got just a tiny bit of colors; blue and yellow (which were in incorrect places), but the rest was still black and white and the image was still inverted (what is supposed to be in dark colors shows as white and what is supposed to be in light colors shows as black.
I am wondering if what I have is a faulty CPU or PPU1, PPU2. Any ideas? Have anybody had this problem before? I would hate to throw away this console, it has a sentimental value to me!!
I have tried to fix the issue by doing the following:
Replaced all smd capacitors with brand new capacitors bought from console5.
Replaced the 21.4772 crystal oscillator with a brand new one.
Checked connectivity of everything that I could test on the mother board, but found no issues.
Replaced the voltage regulator with a 5-volts, 2 amp regulator bought from console5 as well.
Since none of the above seemed to fix the problem, I tried soldering pins 20, 21 and 22 from the BA6592F video encoder directly to the corresponding RGB pins of the multi-out through a cable and 75ohm resistors, and did the same for the csync, but connected it directly without a resistor.
After this, I still got the same black and white inverted (negative) image.
I then tried soldering a 470 uf, 6.3 v capacitor to legs 2 and 3 of the voltage regulator. Amazingly, I got just a tiny bit of colors; blue and yellow (which were in incorrect places), but the rest was still black and white and the image was still inverted (what is supposed to be in dark colors shows as white and what is supposed to be in light colors shows as black.
I am wondering if what I have is a faulty CPU or PPU1, PPU2. Any ideas? Have anybody had this problem before? I would hate to throw away this console, it has a sentimental value to me!!